Packaging materials are used in every manner of everyday life. Corrugated packaging materials were used as early as the 1870s to protect fragile and valuable objects during packing and handling. Many of the paper, paperboard and fiberboard materials used in the manufacture of early corrugated materials are still in use today in their basic form and/or with slight improvements.
In present day use, packaging serves a number of purposes. Aside from traditional protection functions, in many instances, packaging must also serve a pilfer deterrent function. This is particularly so for smaller, more valuable items.
Although traditional packaging, e.g., paperboard or corrugated board, with various coatings serve protection functions well, they do not provide a substantial level of pilfer resistance. As such, more rugged, tear resistant materials have been incorporated into packaging materials to meet today's requirements.
One type of packaging material includes a tear resistant film, such as a cross-oriented, laminated film in a laminate with a paperboard substrate. One such film is a VALERON® film, which is a cross-oriented, laminated polyolefin film commercially available from VALERON® Strength Films, an Illinois Tool Works company, of Houston, Tex. One structure using such a film is disclosed in Amendt, U.S. Pat. No. 7,097,895, which patent is commonly assigned with the present application and is incorporated herein by reference.
While such a laminate better serves both the protective and pilfer resistant requirements for merchandising, the two film layers increase the costs for such packaging. As such, a lower cost option is desirable.
In addition, it has also been found that the level of adhesion of the film to the paperboard substrate can impact the tear resistance of the package. Specifically, it has been found that if the adhesion of the film to the paperboard substrate is too great, tear propagation resistance decreases.
Accordingly, there is a need for a packaging material and a method for making the packaging material that provides protection for the packaged item, as well as a pilfer resistant structure. Desirably, such a material is provided at a low cost, and uses known material elements within the material structure. More desirably still, such a material can be manufactured using known techniques.